CMF welding

[wfopete]

I was thinking of rewelding my CMF frame to make it "better than ever" but after I did a search and read this

http://pentonusa.org/forum/topic.asp?TOPIC_ID=1712&SearchTerms=cmf,welding

I figured it was a not such a good idea.  Of course that was from 2002.  Is there anything out of late that says differently?

Pete Petrick
Penton 175 Jackpiner

[TGTech]

Pete,

I don't know exactly what you're referring to with regard to "welding" your frame, but if you're just welding up cracks, "in the day", we just used a TIG welder and a mild steel rod as opposed to an alloy rod. And I don't remember re-breaking any welds.

Dane

[Kip Kern]

I use a MIG welder and have had no problems at all. .025 wire Argon/CO2 mix, low heat works great #3-#4 on wire speed.  On a lot of the frames, you can still find bits of wire still from the original factory welds.  Happy Holidays!

[bentrims]

Pete,
I can give you up to date photos of a race where doing double jumps on a CMF 125 flattened (squared)both rims and bent the 32mm fork tubes out a couple inches.

One week prior to the race I had two TIG welds done to stop cracks from elongating. One crack was at the lower front motor mount. The other was located near the steering stem / frame mount area. It has been over a year now with 5-6 more tough outings on the bike and no failure to the frame.

If you need this done for safety get-r-dun. If it is for cosmetics...thats your call.

[BrianTaylor]

Well when I posted my question in 2002 I never got an answeron " if I had the only two sloppy welded frames " and now thks Kip  you have answered it for me. By seeing some frames with wire still in the weld pretty well answers it .... thks again Brian

Brian Taylor

[Kip Kern]

Brian Your welcome.  I normally weld the frames really good and then go over or grind off the perfect welds.  I then reweld and leave a "pop" or wire to give the bike the original look.  John Cooper, the best welder I know, taught me that one!;)

[Rocket]

I believe when the CMF frames were welded originally they were stress relieved.  I think this keeps the tubing from cracking right next to the welds.
Rocket

[wfopete]

Thanks guys.  Now all I have to do is find a practice frame to develop my CMF/wirefeed skills on! I have the feeling that a little experiance might help here.

Pete Petrick

[TGTech]

Rocket:
When the frames were manufactured at KTM, they went from the welding department to the shot peening chamber and then right onto the paint line. I don't know if the shot peening chamber was actually designed to stress relieve the frames, but I suppose that it may have helped some. The main purpose of the shot peening was to clean the frames for painting.

Dane

[Rocket]

Dane
That is good to know, I have repaired some frames with a MIG welder and always wondered if it needed to be stress relieved.
thanks
Rod

[Rain Man]

whoo boy, and all along I've been stick welding them back together !!

Raymond
 Down East Pentons